1. Field of the Invention
The present invention relates to a sheet feed roller, such as a feed roller or a transport roller, for transporting paper in a copying machine, a printer or a facsimile machine.
2. Description of the Art
A sheet feed roller used in a copying machine or the like is generally required to maintain a friction coefficient for a long time. However, paper powders caused by papers accumulate on a surface of the sheet feed roller in repeated sheet feeding, so that a friction coefficient decreases, resulting in the problem that sheet feed capability deteriorates.
Therefore, there have been conventionally proposed sheet feed rollers, which incorporate paper powders into grooves formed axially at specific intervals circumferentially on an outer peripheral surface thereof, or recesses of a textured surface thereof (see, for example, Japanese Unexamined Patent Publication No. 11-106067 and Japanese Patent No. 3744337).
In the meantime, there is a method of follow printing (overprinting) on a color-printed paper, as a printing method. In this case, crushed powders are scattered on a paper surface prior to the follow printing, so as to prevent adherence of overlapping paper sheets to each other. However, when the follow printing is conducted in a state that crushed powders are scattered, the crushed powders adhere to the sheet feed roller, sheet feeding capability deteriorates earlier than usual printing even if the sheet feed rollers (having grooves or a textured surface on an outer peripheral surface thereof) disclosed in the above two publications. For this reason, an exchange cycle of the sheet feed roller is shortened, so that maintenance cost increases.
In view of the foregoing, it is an object of the present invention to provide a sheet feed roller prolonging sustainability of sheet feeding capability even if crushed powders are scattered, and a method of manufacturing the same.